Thermal compensating tie beam assembly



Oct. 22, 1968 w. c. NOTBOHM 3,406,931

THERMAL COMPENSATING TIE BEAM ASSEMBLY Filed May 2, 1967 2 Sheets-Sheet1 60 WILLARD c. NOTBOHM Oct. 22, 1968 w. c. NOTBOHM 3,406,931

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FIG-4 .llllllv. v v 0 l w 4 8 1. .I M M m United States Patent 3,406,931THERMAL COMPENSATING TIE BEAM ASSEMBLY Willard C. Notbohm, Watertown,N.Y., assignor to The Black Clawson Company, Hamilton, Ohio, acorporation of Ohio Filed May 2, 1967, Ser. No. 635,600 8 Claims. (Cl.248-2) ABSTRACT OF THE DISCLOSURE A thermal compensating beam which doesnot vary in length due to changes in the ambient temperature. One use isin paper machine dryer sections wherein the side frames which supportthe dryer drums are secured at their lower ends to the concrete floorand are interconnected at their upper ends by tie beams which, becauseof their bimetallic construction, do not change in length as a result oftemperature variations.

Background of the invention In processing machinery such as papermachines for the continuous manufacture of various products in a webform, side frames are provided for supporting the various components ofthe machinery. As the machinery is designed for greater capacity, thespeed at which the web is formed and the width thereof are graduallybeing increased, and it has become necessary to compensate for allcharacteristics of the machinery which might detract from a high qualityend product, as Well as those conditions which are detrimental to theoperation of the machinery itself. One such characteristic is themisalignment of the side frames caused by thermal expansion of thecrossbeams.

Since the side frames are usually anchored to the concrete supportingsurface and interconnected at their top portions by tie beams whichprovide rigidity and accurate spacing to the machinery components, anychanges in the ambient temperatures around the crossbeams tend to causeexpansion of contraction thereof. The lower portions of the framescannot expand or contract due to their connection to the floor, and thusthe upper portions of the frames are forced apart by the expansion ofthe crossbeams so that the side frames are no longer parallel. Thisproblem is especially acute in a paper machine dryer section whereinnumerous drying rolls or drums are heated to a temperature substantiallyabove normal room temperatures. For example, a 100 F. increase intemperature of a tie beam having a length of 360 inches would causeelongation of about V inch in a conventional steel crossbeam. Thisexpansion may cause serious binding on the bearings which support theheavy drying rolls and lead to the eventual failure thereof, not tomention other problems, such as stresses in the anchoring bolts andsoleplates, all created by the thermally induced distortion of the sideframes.

Summary of the invention This invention relates to an improved crosstiewhich does not expand or contract due to change in temperature thereof.Such a crossbeam extends between rigid connections with the side membersof processing machinery and provides the necessary rigidity for holdingthese side members in accurate alignment. The crossbeam includes a pairof side beam members each having one end fixed to opposite ones of theside members and a central expansion member which is rigidly secured tothe free ends of the side members. The central member has a coefficientof expansion approximately twice that of the side members so that, asthe side members each changes in length, the properly designed centralmember changes twice this 3,406,931 Patented Oct 22, 1968 length tocompensate for the expansion of both side members.

Brief description 0 the drawings FIG.l is a side elevation view of apaper machine dryer section utilizing tie beams in accordance with theinvention;

FIG. 2 is an end view of a dryer section constructed according to theprior art;

FIG. 3 is an enlarged section on the line 3-3 of FIG.

FIG. 4 is a plan view of the tie beam assembly;

FIG. 5 is a side view of the'tie beam assembly; and

FIG. 6 is a fragmentary exploded view in perspective of the assembly ofFIGS. 3-5.

Description of the preferred embodiment FIG. 1 shows a fragment of atypical dryer section 10 in which the temperature compensating crosstiesor beams 11 of the invention can be utilized. It includes a pair ofsoleplates 12 supported by columns 13 rigidly secured in the concretefloor 14. Frame members 15 are mounted on the soleplates 12 in a latticearrangement for supporting the various dryer rolls 18 which have theirbearings 20 mounted on these frame members. Upper horizontal beams 22interconnect the top portions of the upper frame members 15 along eachside of the machine. FIG. 1 also shows upper and lower felts 23 and 24between which the paper web 25 is sandwiched in the usual way as itpasses alternately around the rolls 18.

The side frames 15 are interconnected at frequent intervals by crossties11 which extend between the upper horizontal beams 22 to secure theupper portions of the side frames rigidly together so that the bearings20 on the opposite ends of the rolls 18 remain in alignment and so thatrigid alignment of the machinery components is precisely maintained toenable the machinery to operate at high speed.

The problem which the crossties 11 of this invention solve isillustrated in FIG. 2 for a dryer section constructed according to theprior art. The columns 13a extend vertically upward from rigidconnections with the concrete floor 14a or its equivalent. These columnssupport the soleplates 12a and side frames 15a which, in turn, supportthe dryer rolls 18a in bearings 20a, and the prior art cross member 33rigidly interconnects the top ends of the side frames 15a. When themachine is initially installed, it is a simple task to align thevertical side frames 15a so that they are parallel and to position therolls 18a and their bearings 20a so that they operate in alignment freefrom any binding.

When the dryer section of FIG. 2 is started in operation and thetemperature of the rolls 18a heated as required, the crossties 33 havetheir temperature elevated thus expanding and forcing the side frames15a apart so that they are no longer parallel with the consequentdisadvantages set forth above. The columns 13a. and associated buildingstructure do not expand in a similar manner because they are remote fromthe elevated temperatures and which are, in fact, a very large heatsinkwhich tends to stabilize their temperatures.

Referring now to FIGS. 35, the crosstie 11 in accordance with theinvention is illustrated in detail. This crosstie includes two parallelbeam members and 41 in the form of channels having the outwardlyextending flanges 42 and 43 in the top and bottom thereof and theintermediate web portions 45 having flat smooth surfaces on the innerand outer sides thereof, respectively. Sandwiched between these beammembers is the elongated expansion member having a rectangularcross-section with flat surfaces on its opposite sides but shorter thanbeams 40 and 41 so that its ends 51 and 52 are spaced inwardly from bothends of the beam members as shown in FIG. 4. However, the length of theexpansion member 50 may be equal to that of the beams or may be ofdifferential length as the exact length is a function of the dififerencein thermal expansivity of the expansion member and the beam members 40and 41. The beam and expansion members 40, 41 and 50 are preferablycoextensive in height, but the coefficient of thermal expansion of theexpansion member 50 is substantially greater and preferably twice thatof the beam members, e.g., steel and aluminum, respectively.

The left-hand beam member 40 as viewed in FIGS. 3 and 4 has a mountingplate 60 welded or otherwise rigidly secured to one end thereof.Similarly the right-hand beam member 41 as viewed in FIG. 4 has amounting plate 61 secured to the end thereof opposite the mounting plate60. Each of the plates 60 and 61 is rigidly secured, as by bolts 65 tothe respective top beams 22 of the side frames 15. The end of each ofmembers 40 and 41 opposite its mounting plate 60 or 61 is free to slideon the other mounting plate 61 or 60, respectively.

The right and left-hand members 40 and 41 are connected to each otherand to the expansion member 50 by a series of connector assemblies 70constructed and arranged to provide for predetermined relative movementof the members 40, 41 and 50 lengthwise thereof. The connector assembly70 shown in detail in FIG. 3 is one of the two such assemblies whichsecures the end 52 of member 50 to the free end of member 41. As shownin FIG. 3, it includes a stud 75 threaded on both ends to receive a nut76, a spacer sleeve 77, and a washer 78.

The connector assembly 70 in FIG. 3 secures the members 41 and 50 whileproviding for relative sliding move ment of members 40 and 50. Member 41accordingly has a bore 80 receiving the stud 75, but the member 40 has aslot 81 opposite bore 80 which is of sufficient width to receive thesleeve 77 slidingly therein, and approximately three times as long as itis wide. There is an identical con nector assembly 70 vertically alignedbelow the assembly 70 in FIG. 3, as shown in FIG 5, and it will beapparent that the sleeves 77 and washers 78 cooperate with nuts 76 toclamp the end portion of member 50 with respect to the free end of beam41 while providing for sliding movement of these parts relative to thefixed end of beam 40.

Two connector assemblies 70 are provided between the opposite end of themember 50 and the free end of the beam member 40, but as shown in FIG.5, the arrangement of these parts is reversed to secure members 40 and50 together, as indicated by the full line showing of the slots 81.Similar connector assemblies 70a are provided between members 40 and 41beyond the ends of member 50, and they differ from assemblies 70 only inthat their spacer sleeves 77a are longer than the sleeves 77 by adistance approximately equal to the thickness of member 50 to provide aguiding action for relative sliding movement of members 40 and 41.

In the center of the crosstie 11, a connector assembly 70b is providedwhich is itself identical with the assemblies 70a and is similarlymounted in a bore in one of the beam members 40-41, shown as member 40.The other beam member 41 has a slot 82 approximately twice the length ofeach of slots 81 to provide for adequate relative movement of theadjacent portions of members 40 and 41, and there is a similarly longerslot 82 in member 50.

The spacing between the various connector assemblies 70, the length ofthe slots, and the number of connector assemblies is determined by thespecific application of the crossbeam. When considerable length is to beutilized, additional pairs of the connectors can be interposed along thelength of the expansion member 50, similarly to the assembly 70b.

In use, the mounting plates 60 and 61 on the opposite ends of thecrossbeam 11 are rigidly secured to the components of the machinerywhich are to be interconnected 4 so that the distance therebetween willnot vary. For example, in a dryer section, the crossbeam is used tointerconnect the side frames 15 across the width of the machines inclose proximity to the heated dryer rolls 18. The side frames 15 arealigned parallel during installation, and the crossbeams 11 are securedin position to hold this parallel relationship during operation of themachinery.

When the machine commences operation and the temperature of thecrossbeam 11 is elevated, the left-hand member 40 which is secured tothe mounting flange 60 expands upwardly (as viewed in FIGS. 4 and 5) sothat its free end extends a maximum distance. At the same time, theright-hand member 41 expands downwardly from its fixed end on themounting plate 61 so that the lower end thereof extends a maximumdistance. Simultaneously, since the expansion member 50 has acoeificient of expansion in the order of twice that of either of theside members 40 and 41, it expands so that the ends 51-52 thereof arespaced an additional distance from the center thereof.

As a result of the connectors 70, the free ends of the side members 40and 41 are allowed to move with respect to the fixed ends thereof sincethe various spacer sleeves permit the connector assemblies to slide inthe associated slots to compensate for the extension of the side members40 and 41 without detracting from the rigidity of the crossbeam 11. Oneend 52 of the expansion member 50 is connected with the free end of themember 41 so that this end of the expansion member and the adjacent freeend of the member 41 are allowed to expand together. Similarly the otherend 51 of the expansion member 50 and the free end of member 40 areconnected to expand together. Accordingly, the side members 40 and 41have their free ends rigidly interconnected by the expansion member 50.

Stabilization is thus provided to the crossbeam 11 by the slidingconnection between the free ends and adjacent fixed ends of the members40 and 41. The central connector assembly 70b moves with the member 40to one end of the slots in the side and expansion members 40 and 50 thusallowing the member 40 to extend. Thus each of the three members 40, 41and 50 is allowed to expand lengthwise, with the expansion member 50compensating for the change in length of the side members 40 and 41 sothat there is no change in the over-all length of the crossbeam causedby temperature variations. Should the temperature variations bedecreased rather than increased, the reverse of the above operationwould occur, again without variation in the total length of thecrossbeam 11. Accordingly, the invention has provided a thermalcompensating beam 11 for use in processing machinery where expansion andcontraction cannot be tolerated because it will destroy the tolerancesrequired to produce high quality in the product being processed orbecause it will cause damage to the machinery itself due to thermallyinduced misalignment. The tie beam may extend across the width of apaper dryer or the like to interconnect the side frames in order to holdthem in a precise parallel position regardless of changes intemperatures. While the invention has been described in connection witha paper dryer, it should be obvious that it can be utilized in manydifferent types of machinery and other apparatus without departing fromthe scope of the invention.

While the form of apparatus herein described constitutes a preferredembodiment of the invention, it is to be understood that the inventionis not limited to this precise form of apparatus, and that changes maybe made therein without departing from the scope of the invention whichis defined in the appended claims.

What is claimed is:

1. A crossbeam assembly for the side frames of processing machinery andthe like to maintain a predetermined distance between said frames over aWide range of ambient temperature variations, said assembly comprising apair of elongated beam members extending in side by side relation, meansfor securing One end of a first of said beam members to the first of theside frames while leaving the other end thereof free to move relative tothe second side frame, mean-s for securing one end of the second of saidbeam members to the second of said side frames while leaving the otherend of said second beam member free to move relative to the first sideframe, an expansion member having a coefiicient of expansion greaterthan that of said beam members extending in side by side relation withsaid beam members, and fastening means securing said free end of saidfirst beam member to one end of said expansion member and securing saidfree end of said second beam member to the opposite end of saidexpansion member to provide compensation for the expansion orcontraction of said beam members caused by changes in temperature bycorresponding total expansions of contractions of said expansion member.

2. A crossbeam assembly as defined in claim 1 wherein said expansionmember is interposed between said beam members.

3. A crossbeam assembly as defined in claim 1 wherein each of saidfastening means includes a stud member which extends through circularopenings in one of said beam members and said expansion member andthrough an elongated slot in the other of said beam members, and aspacer sleeve surrounding said stud and interposed between saidexpansion member and said other of said beam members to provide forrelative movement between said other of said beam members and saidexpansion member.

4. A crossbeam assembly as defined in claim 1 wherein said expansionmember has a coefficient of thermal expansion which is approximatelytwice that of said first and second beam members.

5. A crossbeam assembly as defined in claim 3 wherein intermediateconnector assemblies are provided between said first and secondfastening means for adding additional rigidity to the assembly whilepermitting relative movement therebetween.

6. A crossbeam assembly as defined in claim 3 wherein said expansionmember has a length less than that of said beam members, and comprisingconnector assemblies interposed between said beam members in the spacebeyond the ends of said expansion member to add rigidity and strength tothe assembly while permitting relative movement between said sidemembers.

7. A crossbeam assembly as defined in claim 1 wherein a plurality offastening means in addition to said first and second fastening means areprovided between said beam and expansion members for adding strength andrigidity to the assembly while permitting relative longitudinal movementbetween said members to compensate for thermal expansion thereof.

8. A crossbeam assembly as defined in claim 2 wherein said beam membersare channel shaped, and said expansion member has a rectangularcross-section, said beam members having their flat sides diasposed incontact with the flat sides of said rectangular expansion member.

References Cited UNITED STATES PATENTS 1,986,132 1/1935 Bigelow 1032182,356,721 8/1944 Hagemann 24819 2,920,850 1/1960 Campbell 2481462,981,463 4/1961 Dagrell 248-2 XR 3,066,449 12/1962 Cramer 52-294 JOHNPETO, Primary Examiner.

